"Warning! The following stories did not really happen! (...they don't count for the Spider-Man in Amazing Spider-Man, before or after Brand New Day...)"

This declaration of non-canonicity clearly applies to three of the four stories in the comic, but what about "Street Monsters?"

At first glance, it looks like it could be canonical. It's a Spidey team-up story with the Falcon that appears to date from the period of time after Falcon decided in CA 138 that Spidey wasn't a criminal despite the webhead's reputation and before Falcon got his red and white costume in CA 144. A rather small window.

On second glance, two possible problems are evident:
1) The costume Falcon wears in KSSMSS is not quite identical to his original costume; there are a few color variations here and there. Probably not a big continuity wrecker.
2) Spidey learns in KSSMSS that Sam Wilson is the Falcon. I don't know if a story set later in time (say, M/TU 30?) demonstrates that Spidey does not know the Falcon's identity. Potentially a continuity wrecker, unless the story in KSSMS can be placed later and the costume attributed to a short-lived, never-before-seen change of pace for Falcon.

Remember the Prime Directive of Canon. For our purposes, a story is canon unless A) it can't be, or B) Marvel says it isn't. Therefore, even if a story could be canon, if Marvel says it didn't happen, then it didn't.